Watch contact post



June 19, 1962 H. RUEGER 3,040,150

WATCH CONTACT POST Filed Sept. 5, 1958 so I m. 5. INVENTOR Herman RuegerATTORNEYJ United States Patent 3,049,150 WATCH CGNTACT POST HermanRneger, Lancaster, Pa., assignor to Hamilton Watch Company, Lancaster,Pa., a corporation of Pennsylvania Filed Sept. 5, 1958, Ser. No. 759,2901 Claim. (Cl. 200-166) This invention relates to electric time piecesand more particularly to an improved contact assembly for electric timepieces.

The problem of small size is one which the watch and clock industry hascontinuously lived with and has for the most part conquered. However,with the advent of battery operated clocks of small size entirely newproblems have arisen and success in the production of clocks is largelydependent on the success of their solution. One such problem is found inconnecting the live wire from the battery to a suitable contact postagainst which a movable contact is periodically brought to bear. Thesmall size of the wire, the miniature size of the post and its generalinaccessibility renders manufacture ditficult. The use of solder is notpractical and a conventional screw coupling would be so small as torender the connection inadequate.

It is accordingly a primary object of the present invention to provide acontact post assembly which is satisfactory in operation and whichpermits practical and economical manufacture.

It is another object of the invention to provide an assemblage of theforegoing type utilizing an insulating post supporting an insulated wireand a contact sleeve wherein the act of assembling the parts makes goodelectrical connection between the wire and sleeve.

It is a still further object of the present invention to provide asleeve for making contact with a current carrying wire which will, atthe same time, provide a contacting surface which will not oxidize underordinary conditions.

These and further objects and advantages of the invention will becomemore apparent upon reference to the attached specification and claim andappended drawings wherein:

FIGURE 1 is a vertical elevation of the contact post partly in section;

FIGURE 2 is a view similar to FIGURE 1 at a 90 angle to the view ofFIGURE 1;

FIGURE 3 is a top plan view of the post with wire and retainer sleeveassembled;

FIGURE 4 is a vertical elevation of another embodiment of a contactpost, partly in section;

FIGURE 5 is a vertical elevation of still another embodiment of acontact post, partly in section; and

FIGURE 6 is a plan view of another embodiment of a retainer sleeve.

Referring to the drawings, the contact post is intended for use mecontact arrangement of the general type shown in the co-pendingapplication Serial No. 631,850 of Daniel Fritsch, filed December 31,1956, now Patent No. 2,926,534 and is shown without any of theadditional details of the electric watch. The post is primarily designedto be used in a battery operated electric clock, the post itself beingapproximately one-tenth of an inch in diameter and three-tenths of aninch long.

Referring particularly to FIGURES l, 2 and 3 of the drawing, plate 10 ina battery operated electric clock supports a post 12 which is formed ofan insulating material. The upper and lower edges of the post 12 arebevelled at 14 and 16 to permit easy insertion of the post into theopening 18 of the plate 10 and to permit 3,040,155 Patented June 19,1952 easy mounting of the retainer sleeve over the post in a manner tobe presently described. A diametric slot 20 is formed at the upper endof the post and is of sutficient width and depth to receive the end ofan insulated wire 22 which may be connected to a battery in the clock(not shown). The wire 22 may be formed with an oxide or other coating asinsulation and its free end 24 extends beyond the slot 20 a distanceequal approximately to the diameter of the post.

A retainer sleeve 26 is formed of an inner lamination 28 of brass or asimilar metal and an outer lamination 30 of silver or other metal whichwill provide good contact and not be subject to oxidation under normaloperating conditions. Bimetallic strips from which such a sleeve may beformed are commercially available. Referring to FIGURE 3, it is seenthat the retainer sleeve 26 is broken or split at 32 so as to have aresiliently variable inner diameter.

In forming the assemblage shown in FIGURE 1, the wire 22 is laid throughthe slot 20 with the free end 24 extending beyond the post a distanceequal approximately to the diameter of the post. The sleeve 26 is thenforced down over the post and wire. As the lower edge of the sleeveengages the Wire on both sides of the post, it strips away theinsulating coating on the wire so that intimate electric contact isestablished between the bared wire and the inside of the sleeve. Thebevelling 14 at the upper end of the post 12 facilitates the mounting ofthe sleeve and it will be appreciated that the act of mounting thesleeve at one and the same time, mechanically locks the wire to the postand establishes electric contact to the sleeve.

While the sleeve is preferably slit as shown at 32 in FIGURE 3 in orderto provide resilience, it will be understood that such a split is notnecessary and that the sleeve may be provided in an unbroken form ofsuch a diameter as to effectuate the same purpose.

The outside of the sleeve is adapted to be engaged or contacted by aspring contact arm (not shown) which is intermittently brought intocontact with the sleeve through the operation of a toothed wheel, as isdiscussed in detail in the aforementioned co-pending application.

Referring to FIGURE 4, there is shown another embodimeut of theinvention wherein a plate 3-4 has mounted in an opening 36 therein, aninsulating post 35. The post 38 is bevelled at both ends at 44) and 42as in the preceding embodiment of the invention. According to thisembodiment, the slot of FIGURES 1 through 3 is replaced with a diametrichole or bore 44 extending through the upper portion of the post. Aninsulated wire 46 has its end passed through this hole 44 so that thefree end of the wire 48 extends beyond the post on the other side. Ametallic sleeve 50 having an inner lamination 52 of brass or similarmetal and an outer lamination 54 of silver or similar metal is forceddown over the post and Wire to mechanically lock the wire in positionand establish electrical contact with the sleeve.

Referring to FIGURE 5 there is shown still another embodiment of theinvention wherein an insulating post 56 is mounted in an opening 58 in aplate 6! According to this embodiment of the invention the post 56 isaxially bored at 62. That is to say, the post is hollow. The top andbottom edges of the post 56 are bevelled at 64 and 66 as in the previousembodiments of the invention for the same purpose.

A diametric slot is cut through the top of the post and forms slots 68and 70 in the peripheral walls of the cylindrical post. According tothis embodiment of the invention, a wire 72 may be fed into the interiorof the post 56 from the bottom thereof as shown at 74 and looped overone wall of the post as shown at 76.

A retainer sleeve 78 formed of an inner lamination 80 of brass orsimilar metal and an outer lamination 82 of silver or similar metal isforced down over the top of the post and the wire end 76 to mechanicallylock the wire in position and establish electrical contact as in thepreceding embodiments of the invention.

While the retainer sleeves discussed in connection with all of thepreceding embodiments of the invention have been of a bi-metallic naturethroughout their periphery, it is also within the purview of theinvention to use a retainer sleeve formed of a single metal but having amore precious metal inlaid in the outer surface of the sleeve at thecontact position only. Thus, referring to FIGURE 6 there is shown asleeve 84 of brass or similar metal having an inlay 86 of silver or asimilar good contact metal which will not oxidize under normal operatingconditions.

It will be apparent from the foregoing that a contact formed in themanner of the invention is quite simple and may be economicallyproduced. With bi-metallic sleeves of the type shown in FIGURES 1through 5 of the drawings, it is possible to continuously renew thecontact area by simply rotating the sleeve about the post. While roundor cylindrical posts and sleeves are the most economical, it will alsobe appreciated that other shapes could be used where desired.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claim rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claim are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

A horological device having a post mounted electrically conductive firstcontact sleeve engageable by a second contact movable relative to saidpost comprising: an insulating post having a diametric bore therein; aninsulated wire extending through said bore and along the sides of saidpost; an electrically conductive first contact sleeve fitting tightlyabout said post and frictionally gripping the portions of said Wirealong the sides of said post; said first contact sleeve is of alaminated construction having inner and outer electrically conductivelayers of different compositions; the composition of the outer layerbeing substantially non-oxidizable under normal operating conditions ofsaid device; insulation stripping means on said sleeve engageable withthe portions of said wire along the sides of said post for stripping theinsulation from the portions of said wire along the sides of said post,whereby an electrical contact will be made between said first contactsleeve and the stripped portions of said wire so that an electricalconnection will be made between said second contact and said wire uponthe engagement of said second contact with said first contact sleeve.

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